This invention relates to electromagnetic actuators that essentially include at least one electromagnet and an armature which is coupled to a setting member to be operated. The armature, upon energization of the electromagnet, is movable against the force of a resetting spring. Such actuators are characterized by high switching speeds. The electromagnets, however, involve the problem that as the armature approaches the pole face of the electromagnet (that is, the distance between armature and pole face continuously decreases), the magnetic force affecting the armature increases. As a result, the armature is further accelerated and thus impacts on the pole face with high speed. Apart from noise generation, rebound phenomena may occur, that is, the armature may move away from the pole face at least for a short period until it eventually assumes its position of rest at the pole face. This phenomenon may adversely affect the functioning of the setting member, resulting in significant operational disturbances, particularly in actuators which have a high switching frequency.
It is therefore desirable to ensure that the impact speed has a value in the order of magnitude of 0.1 m/s. It is of importance that such small impact speeds are ensured even under real operating conditions including all the relevant stochastic fluctuations and interfering external influences such as jars or the like.